Indoor coverage of universal mobile telecommunications system (UMTS) signals has always been a problem that is confronted by users and operators. The advent of the Femto network is a good solution to this problem. Key network elements of the Femto network are a home NodeB (HNB) and a home NodeB gateway (HNB-GW). The HNB uses a standard air interface; a fixed broadband access network is used between the HNB and the HNB-GW as a backhaul network; after convergence of the HNB-GW, a standard Iu interface is used to access the core network, and in this way supplemental coverage of macro cell signals is achieved. Moreover, a Femto cell has a small coverage range, capable of conducting user services more finely. Therefore, the Femto network is receiving more and more attention from the operators.
Location management is one of the most important functions of devices at the core network (CN) side and at the radio access network (RAN) end. When a user equipment (UE) from coverage of a cell gradually enters coverage of another cell, a radio network controller (Radio RNC) of the original cell and an RNC of the new cell complete context switch through signaling exchange, to ensure that the UE is capable of receiving or initiating services in the new cell. The 3rd generation partnership project (3GPP) defines a handover (relocation) process to meet requirements of the foregoing context switch between RNCs. According to different implementation manners, the handover is categorized into hard handover and soft handover. For the soft handover, an Iur interface is used to manage radio resources between RNCs, so that without context transfer, a UE is capable of entering a new cell in a lossless manner. Comparatively speaking, the soft handover has better user experience and a higher success rate of handover, and therefore, the soft handover is a preferred handover manner in a macro network.
However, due to a special nature of the Femto network, the 3GPP fails to define implementation of the soft handover in the Femto network currently. Therefore, when a macro cell is adjacent to an HNB cell, a soft handover process fails to be initiated.